How much do I have to pay for media spend on BrandGen?

We recommend $5-10/Mo per company. However, there is no minimum spend.

There is no minimum spend but you will need to fund campaigns to a sufficient level to bid and serve ads. This means that the campaign budget needs to exceed your minimum bid at minimum. 

We recommend $5-10/Mo per company. Enterprise companies bias on the high side of that, mid-market companies toward $5. So for a target set of 500 companies you could assume a monthly budget of $2,500 - $5,000.